In contrast to vital statistics data, which are typically collected continuously and summarized on an annual basis, censuses typically occur only every 10 years or so, and thus are not usually the best source of data on births and deaths. Analyses are conducted after a census to estimate how much over or undercounting took place. These compare the sex ratios from the census data to those estimated from natural values and mortality data. Censuses do more than just count people.


KAON2 is developed as a joint effort of the Information Process Engineering (IPE) at the Research Center for Information Technologies (FZI), the Institute of Applied Informatics and Formal Description Methods (AIFB) at the University of Karlsruhe, and the Information Management Group (IMG) at the University of Manchester. KAON, TextToOnto, and Text2Onto are open source, based on Java. KAON2 is not open source, but the executable can be downloaded from the KAON2 site. KAON home page. KAON2 home page.

Formal system

logical systemdeductive systemsystem of logic
Like languages in linguistics, formal languages generally have two aspects: In computer science and linguistics a formal grammar is a precise description of a formal language: a set of strings. The two main categories of formal grammar are that of generative grammars, which are sets of rules for how strings in a language can be generated, and that of analytic grammars (or reductive grammar, ) which are sets of rules for how a string can be analyzed to determine whether it is a member of the language. In short, an analytic grammar describes how to recognize when strings are members in the set, whereas a generative grammar describes how to write only those strings in the set.


universitiesresearch universitiescollege
A university (universitas, 'a whole') is an institution of higher (or tertiary) education and research which awards academic degrees in various academic disciplines. Universities typically provide undergraduate education and postgraduate education.

Method of analytic tableaux

analytic tableauanalytic tableauxsemantic tableau
In proof theory, the semantic tableau (plural: tableaux, also called 'truth tree') is a decision procedure for sentential and related logics, and a proof procedure for formulae of first-order logic. An analytic tableau is a tree structure computed for a logical formula, having at each node a subformula of the original formula to be proved or refuted. Computation constructs this tree and uses it to prove or refute the whole formula. The tableau method can also determine the satisfiability of finite sets of formulas of various logics. It is the most popular proof procedure for modal logics (Girle 2000).


magic sets
Datalog is a declarative logic programming language that syntactically is a subset of Prolog. It is often used as a query language for deductive databases. In recent years, Datalog has found new application in data integration, information extraction, networking, program analysis, security, and cloud computing.


The comorbidities identified by the Elixhauser comorbidity measure are significantly associated with in-hospital mortality and include both acute and chronic conditions. van Walraven et al. have derived and validated an Elixhauser comorbidity index that summarizes disease burden and can discriminate for in-hospital mortality. In addition, a systematic review and comparative analysis shows that among various comorbidities indices, Elixhauser index is a better predictor of the risk especially beyond 30 days of hospitalisation.

DARPA Agent Markup Language

DAMLDARPA's Agent Markup Language
The DARPA Agent Markup Language (DAML) was the name of a US funding program at the US Defense Advanced Research Projects Agency (DARPA) started in 1999 by then-Program Manager James Hendler, and later run by Murray Burke, Mark Greaves and Michael Pagels. The program focused on the creation of machine-readable representations for the Web. One of the Investigators working on the program was Tim Berners-Lee and to a great degree through his influence, working with the program managers, the effort worked to create technologies and demonstrations for what is now called the Semantic Web and this in turn led to the growth of Knowledge Graph technology.

Computational problem

computational problemsproblemdecision problem
In theoretical computer science, a computational problem is a mathematical object representing a collection of questions that computers might be able to solve. For example, the problem of factoring

Syntax (logic)

syntaxsyntacticlogical syntax
Formation rules are a precise description of which strings of symbols are the well-formed formulas of a formal language. It is synonymous with the set of strings over the alphabet of the formal language which constitute well formed formulas. However, it does not describe their semantics (i.e. what they mean). A proposition is a sentence expressing something true or false. A proposition is identified ontologically as an idea, concept or abstraction whose token instances are patterns of symbols, marks, sounds, or strings of words. Propositions are considered to be syntactic entities and also truthbearers. A formal theory is a set of sentences in a formal language.

College transfer

transferacademic transfertransferred
College transfer is the anticipated movement students consider between education providers and the related institutional processes supporting those secondary and post-secondary learners who actually do move with completed coursework or training that may be applicable to a degree pathway and published requirements.


. * Introduction to Description Logics DL course by Enrico Franconi, Faculty of Computer Science, Free University of Bolzano, Italy

World Wide Web Consortium

W3CrecommendationWorld Wide Web Consortium (W3C)
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web (abbreviated WWW or W3).


conceptsabstract conceptconception
There are six primary arguments summarized as follows: Prototype theory came out of problems with the classical view of conceptual structure. Prototype theory says that concepts specify properties that members of a class tend to possess, rather than must possess. Wittgenstein, Rosch, Mervis, Berlin, Anglin, and Posner are a few of the key proponents and creators of this theory. Wittgenstein describes the relationship between members of a class as family resemblances. There are not necessarily any necessary conditions for membership, a dog can still be a dog with only three legs. This view is particularly supported by psychological experimental evidence for prototypicality effects.

Ronald Fagin

Ronald Fagin (born 1945) is an American mathematician and computer scientist, and IBM Fellow at the IBM Almaden Research Center. He is known for his work in database theory, finite model theory, and reasoning about knowledge.

Ground expression

ground termgroundground atom
In mathematical logic, a ground term of a formal system is a term that does not contain any free variables.

Course credit

creditcreditscollege credit
A credit is the recognition for having taken a course at school or university, used as measure if enough hours have been made for graduation.


An axiom or postulate is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments. The word comes from the Greek axíōma (undefined) 'that which is thought worthy or fit' or 'that which commends itself as evident.'

Unary operation

unaryunary operatormonadic
In mathematics, a unary operation is an operation with only one operand, i.e. a single input. This is in contrast to binary operations, which use two operands. An example is the function f : A → A, where A is a set. The function f is a unary operation on A.

Predicate (mathematical logic)

In mathematical logic, a predicate is commonly understood to be a Boolean-valued function P: X→ {true, false}, called the predicate on X. However, predicates have many different uses and interpretations in mathematics and logic, and their precise definition, meaning and use will vary from theory to theory. So, for example, when a theory defines the concept of a relation, then a predicate is simply the characteristic function (otherwise known as the indicator function) of a relation. However, not all theories have relations, or are founded on set theory, and so one must be careful with the proper definition and semantic interpretation of a predicate.

Knowledge base

knowledgebaseknowledge basesknowledge-based
A knowledge base (KB) is a technology used to store complex structured and unstructured information used by a computer system. The initial use of the term was in connection with expert systems which were the first knowledge-based systems.

Closed-world assumption

closed world assumptionclosed domain of discourseclosed
In the following description, the considered knowledge base K is assumed to be propositional. In all cases, the formalization of the closed-world assumption is based on adding to K the negation of the formulae that are “free for negation” for K, i.e., the formulae that can be assumed to be false. In other words, the closed-world assumption applied to a knowledge base K generates the knowledge base The set F of formulae that are free for negation in K can be defined in different ways, leading to different formalizations of the closed-world assumption.


Education is the process of facilitating learning, or the acquisition of knowledge, skills, values, beliefs, and habits. Educational methods include storytelling, discussion, teaching, training, and directed research. Education frequently takes place under the guidance of educators and also learners may also educate themselves. Education can take place in formal or informal settings and any experience that has a formative effect on the way one thinks, feels, or acts may be considered educational. The methodology of teaching is called pedagogy.

Open-world assumption

open world assumptionepistemic uncertaintyopen world
In a formal system of logic used for knowledge representation, the open-world assumption is the assumption that the truth value of a statement may be true irrespective of whether or not it is known to be true. It is the opposite of the closed-world assumption, which holds that any statement that is true is also known to be true.

Intersection (set theory)

intersectionintersectionsset intersection
In mathematics, the intersection A ∩ B of two sets A and B is the set that contains all elements of A that also belong to B (or equivalently, all elements of B that also belong to A), but no other elements.